David Stern has drawn his line in the sand… we think. There are still a lot of questions that need to be answered about where that line is and what is and is not allowed.

But the NBA has brought the hammer down. A big hammer.

The NBA has fined the San Antonio Spurs $250,000 for sending Tim Duncan, Tony Parker, Manu Ginobili and Danny Green home and not having them available to play against the Miami Heat in a nationally televised game on Thursday night. Stern pretty much had no choice but to fine the Spurs after he came out before the game with a statement saying there would be “substantial sanctions” on the Spurs for their actions.

Here is Stern’s statement with the fine:

“The result here is dictated by the totality of the facts in this case. The Spurs decided to make four of their top players unavailable for an early-season game that was the team’s only regular-season visit to Miami. The team also did this without informing the Heat, the media, or the league office in a timely way. Under these circumstances, I have concluded that the Spurs did a disservice to the league and our fans.”

As for what rule the Spurs violated, here is what the league said in its release: “The Spurs’ actions were in violation of a league policy, reviewed with the NBA Board of Governors in April 2010, against resting players in a manner contrary to the best interests of the NBA.”

The large fine was aimed at the ownership group led by Peter Holt, clearly wanting them to be the heavies next time Gregg Popovich wants to rest his best players.

Can teams rest players later in the season as we get closer to the playoffs? Is this simply a matter of notification — if Popovich had said he was going to do this three days in advance could the Spurs have avoided the fine? Is the league now going to be into scrutinizing lineups, especially since you can be sure some teams will suddenly have players who have minor injuries that need a night off to rest?

This completely feels like David Stern sending the message to NBA coaches and teams not to mess with nationally televised games, the marquee games. Don’t go resting Kobe Bryant on Christmas, Mike D’Antoni.